Brake adjusting mechanism



Allg- 20, 1935. c. G. KELLER 2,012,011

BRAKE ADJUSTING MECHANI SM Filed May 25, 1933 INVENTOR ATTO R N EYS Patented Aug. 20, 1935 UNITED STATES PATENT OFFICE 2,012,011 BRAKE ADJUSTING MEcHANTsM Charles G. Keller, Hyde Park, N. Y. YApplication May 25, 1933, Serial No. 672,770

11 Claims.

In various types ofbrakes, wear occurs and causes an increase in clearance between the rotatable and non-rotatable members when the parts are in released position.

One object of this invention is to provide an improved mechanism for easily, accurately and quickly eiecting adjustments of this clearance to maintain a substantially constant lining clearance in released position of the brake. This mechanism includes an interm'eshing worm and worm wheelenclosed in a housing, and a further object of this invention is to provide certain improvements in such housing for supporting said gearing and connecting it in place.

Still another object is to provide a housing -which may be easily and inexpensively constructed of sheet metal, and which may be easily assembled to enclose and provide supports for the gearing.

. My improved gearing and housing may be employed for other purposes other than as part of a brake adjusting mechanism. 'e

My improved housing in its preferred embodiment is formed from two U-shaped metal mem- 5 bers cut and bent from sheet or plate stock, vand intertted into opposed crosswise relationship, with the arms of one member extending between the arms of the other to form the side walls of the housing, and with the bases ofsaid members forming the end Walls of said housing.- As a further feature,'the bases of said members are curved to conform substantially with the 4peripheries of the worm and`worm wheel to form a compact unit.

The abutting edges of the U-shaped members may be secured together in any suitable manner, preferably by welding, although they may be provided with suitable interlocking parts for fastening the'membe'rs together.- Even if such interlocking parts be employed, it is advantageous that the abutting edges of the members be soldered together so that the housing will be substantially liquid tight and may hold grease or other lubricant therein.

As another1 feature, the worm and worm wheel are provided adjacent to their ends'with spacers engaging the curved end walls and the side walls of the housing, and serve thereby to support said worm and worm wheel in fixed operative position in said housing.

In the accompanying drawing` there is shown for the purpose of illustration, one embodiment of the present invention. In the drawing:

Fig. 1 is a fragmentary plan View of a brake (Cl. 18S-196) adjusting mechanism embodying my invention, and v Figs. 2 and 3 are sections taken in 'planes at right angles to each other, Fig. 3 being taken on the line 3-3 of Fig. 2.

vThe brake adjusting mechanism, in the form shown, includes a Worm vWheel I0 mounted on a shaft II, and meshing with a worm I2 supported on a shaft I3 which is integral or otherwise connected thereto, and which has an end portion yIll shaped to receive a suitable turning tool.

This gearing is enclosed in a housing I5 comprising a pair of U-shaped members land I1 stamped from sheet metal and intertted in crosswise Opposed relationship, with the arms 'of one member extending between the arms of the other to form the side walls of the housing, and with the bases of said members forming the end walls of said housing. The outer ends of the arms 0f one lU-shaped'member are curved concentrically with the axes of the gears and to partially encircle said gears. The edges of one member may substantially abut the edges of the other member to form an angular recess or. groove-28 along the juncture of the two members, 25 so that these members may be easily welded t0- gether along said juncture as shown.

The U-snaped member I1 has openings I9 in 4the arms thereof to permit the shaft I I to extend through the housing. For supporting the 30 gear Il) in position in the housing I5, there are provided spacers shown in the form of annular Washers or collars 20 mounted on reduced end 4portions of said worm Wheel. These collars 20 serve `as bearings for the wheel andhave their outside diameters slightly greater than the maximum diameter of the worm wheel I0. The `baseof the U-shaped member I6 is so curved as to peripherally engage said collars along substantially one-half of the peripheries thereof, and thereby space said worm Wheel radially from said base.

The collars 2,0 serve not only to space the worm wheel IU radially from the base of the U-shaped member I6, but also serve to axially position said wheel between the arms of the U`shaped member I'I. For that purpose, the outside radial surfaces of the collars 20 extend axially beyond the ends of the worm wheel I0, and engage the arms of the member I'I.

The Worm I2 is similarly held in position in the housing I5 by spacers in the form of annular washers or collars 2| encircling the shaft I3 at opposite ends of said worm to serve as bearings therefor, and having outside diameters slightly greater than the outside diameter of said worm. The base of the U-shaped member I1 is semi-cylindrical in shape, and has the inner radius thereof equal to the outer radii of said collars 2| to engage the peripheries of said collars and space said worm radially inwardly from said base. These collars 2| also engage the arms of the U-shaped member I6 to hold the worm I2 against axial movement.

In order to facilitate the mounting of the worm I2 in position in the housing I5, and in order to permit the end portion I4 of the shaft I3 to extend beyond the housing, one of the arms of the U-shaped member IB is provided with a U-shaped slot22 extending to the outer end of said arm, and having a width only slightly larger than the diameter of the shaft I3. In order to prevent admission of dust or dirt and the escape of grease or other lubricant from the interior of the housing I3 through the slot 22, there ls provided a felt washer 23 encircling and rmly engaging the shaft I3 closely adjacent tothe outer surface of the member I6, and having a portion thereof thick enough or supplemented by an additional piece of felt to ll the end portion of the slots 22 and extend into engagement with the outer surface of one of the collars 2 I.

The felt washer 23 may be maintained in position in any suitable manner 'but preferably by means of a cap 25 pressed thereagainst, and having a peripheral flange 21 encircling the washer. This cap 25 has a central aperture slightly smaller than the diameter of the shaft I3, and has a radial-slit 30 to permit expansion and permit said cap to be forced along the shaft I3 until.

the inner periphery of said cap snaps into a pe'- ripheral groove 3l provided on said shaft.

Means may be provided whereby lubricant, such as grease, may be introduced into the interior of the housing I5. For that purpose, one' of the casing members, preferably the member I6, has a tapped hole 32 for receiving a nipple of standard type. 'Ihe grease delivered tothe housing I5 through said nipple finds its way t0 the teeth of the Worm and wormwheel, and is prevented from escaping through the op(enlngs I9 and 22 by means of the collars.20 kand 2| and the felt washer 23. i l

In order that the housing may be operatively connected as a part of the brake operating mechanism, there is welded or .otherwise oonnected to the outside of the curved portion of the U-shaped member I1, a lug 33-having an aperture 34 lined with a bushing for receiving a pivot pin 35 for connecting it to the yoke 36 of an operating rod 3 1. Any other suitable means may be formed or attached to the casing for engaging said rod, and extending in any suitable direction depending on the relative positions of the rod and cam shaft. It might take the form of a sleeve secured to the housing coaxial with the worm wheel, and having an arm of the length and extending in the desired direction.

In assembling the brake adjusting mechanism, the worm wheel lII) and the collars 2D are inserted in the U-shaped member I6 until said collars are seatedupon the base of said member. The worm I2 and the shaft I3 with the collars 2l are then placed in position in the Vopen end of the U-shaped member I6, with the shaft in and between the arms of the U-shaped member I6 until the collars 2I seat in the base thereof.

'I'he juncture between the members I6 and I1 is then welded, and the felt washer 23 and the cap 25 are fitted in position.

The brake adjusting mechanism may be mounted in any suitable position on a motor vehicle to permit such adjustment from time to time as will compensate for the wear on the band lining. In Fig. 1 is shown one manner in which it may be mounted. In this construction, there is shown a rear wheel axle 48 enclosed in a stationary axle housing 42. Extending substantially parallel to the axle 40 is a rocker cam shaft Il Which operates an internal expanding brake disposed in the brake drum 4I. The end of this shaft is splined to receive the worm wheel I0, and may be threaded to receive a nut 43, orapertured to receivel a cotter pin. A 'washer 4B may be used between the worm wheel and the nut or cotter pin to hold the complete assembly in position on the shaft II.

The cam shaft II is shown journaled at a bracket 44 fixed on the stationary axle housing 42. The rod 31 may be-operated in any suitable manner from a brake lever, an air cylinder or foot pedal.

When it is desired to adjust the brake shoes, a. suitable wrench or other tool is applied lto the end portion I4 of the shaft I3 and the latter is rotated to turn the wormwheel IU and the rock shaft Il, so that any wearin the engaging parts of the brake iscompensated for by moving the brake shoes :or the like closer to the drum when the parts are in released position.

Although the casing or housing is preferably in the form of two U-shaped members, so far as certain aspects of the invention are concerned, the

Vcasing may be two stamped metal sections which may meet in'and be `welded together in the plane of Fig. 2.

. Having thus described my invention, what I claim as new and desire to secure by Letters Patent isz- 1. A brake adjusting mechanism including a worm wheel, a worm meshing therewith, and a housing for said worm and worm wheel, and including a pair of U-shaped members interfitted in opposed crosswise relationship, with the arms of one member extending across the open sides of the other to form the side walls of the housing,

and with the bases of said members forming the end walls of said housing, said bases being semicylindrical in `shape and said side walls having bearings concentric with said bases and with the axes of said worm and worm wheel respectively.

2. A housing for enclosing an intermeshing of the other member to forman angular recess around the juncture of the two members, and said members being welded together along'said juncture.

` 3. In combination, a pair of U-shaped members intertted in opposed crosswise relationship, with the arms of one member extending across the open sides of the other to form a housing, one of said members having a semi-circular base, and the other of said members having apertures coaxial with said base, a. pair of intermeshing gears in said housing, and annular collars coaxial with one of said gears and peripherally engaging said semi-circular base for supporting said gear on said latter base.

4. In combination, a worm and a Worm wheel meshing therewith, a housing for said worm and worm Wheel, comprising a pair of U-shaped sheet metal members intertted in opposed crosswise relationship, with the arms of one member extending across the openvsides of the other to form the side walls of said housing, and with the bases of said members forming the end walls of said housing, and annular spacing members within said housing and adjacent to the ends of said worm and Worm wheel respectively and engaging the end Walls of said housing for supporting said worm and worm wheel in position against movement transverse to thev axes thereof.

5. In combination, a worm, a worm wheel meshing therewith, a housing for said worm and worm wheel, comprising a pair of U-shaped sheet metal members intertted in opposed crosswise relationship, with thearms of one member extending between the arms of the other isoform the sidewalls of said housing, and with the bases of said members forming the end walls of. said housing, the bases of said members being semicylindrical in shape, and annular members at the ends of said worm and worm wheel, and having outer diameters greater than the outside diameters of said worm vand worm Wheel respectively, said members engaging the bases of said U-shaped members and the inner surfaces of the side walls of said. housing to support said worm and worm wheel in operative position in said housing.

6. In combination, a pair of U-shaped members intertted in opposed crosswise relationship, with the armsof .one member extending across the open sides of the other to form the side walls of a housing, and with the bases of said members formingthe end Walls of said housing, a Worm wheel in said housing, a shaft for supporting,v said worm Wheel, and extending through one arm of one of said members, aworm meshing with said worm wheel, a shaft for supporting said worm, and having an end portion extending through an 'arm of the other of said members, and adapted to receive a suitable turning tool for rotating said worm, and annular collars adjacentto the ends of said worm and worm wheel respectively and engaging the inner surfaces of side and end walls of said housing for supporting ,said worm'and worm wheel insaid housing.

7. Incombination, a shaft, a worm on said shaft, a wormwheel meshing with said- Worm, a

housing for said worm and worm wheel, comprisingV av pair of sheet metal members welded together and presenting curved end Walls, one -coaxial with the worm and the other coaxial with the worm wheel, collars entirely -within said housing and coaxial with said worm and worm wheel, seating on the end walls of said housing, and held in place solely by contact with said worm, worm wheel andcasing, means for con- 'necting said worm wheel to 'a cam shaft, means connected to said first mentioned shaft and extending outside of said housing for detachably receiving a turning tool, and means connected to said casing for attaching said housing to an operating mechanism, whereby said worm wheel may be rocked about its axis.

8. In combination, a worm wheel having annular hub portions, a pair of collars encircling said hub portions and of slightly greater outside diameters than said worm wheel, a worm meshing with said worm wheel and having a shaft, a pair of collars entirely within said casing encircling said shaft at opposite ends of said worm and of slightly greater outside diameters than said worm, and a casing having substantially semi-cylindrical end Walls, one of said Walls engaging and supporting the first mentioned pair of collars, and the other end wall engaging and supporting the other pair of collars.

9. Infcombination, a worm wheel having annular hub portions, a pair of collars encircling said hub portions and of slightly greater outside diameters than said worm wheel, a worm meshing with said worm wheel and having a shaft, a pair of collars encircling said shaft at opposite ends of said Worm and of slightly greater outside diameters than said worm, and a casing. h'aving side walls and substantially semi-cylindrical end walls, one of said walls engaging and supporting the first mentioned pair of collars, andthe other end wall engaging and supporting the other'pair of collars, said side walls engaging thel opposite outer surfaces f said collars, and one side wall having an aperture through which one end of said shaft extends, and said Worm wheel and another of said side walls having.alined passages to receive a second shaft.

l0. In combination, a 'worm wheel having a passage therethrough, a shaft extending through said passage and held against rotation in respect to said worm Wheel, a pair of collars encircling said worm wheel at opposite ends, and projecting axially beyond the ends of the worm wheel and radially beyond the periphery of the worm wheel, a worm meshing vWith said Worm wheel,

and a casing for said collars, worm and worm wheel and having a 'substantially semi-cylindrical end wall providing a seat for said collars and having side walls engaging with the ends -of said collarsto position said worm wheel.l y.

11.*In combination, a worm wheel, a worm meshing therewith, said worm and said wormwheel each having axially extending bearing portions, two pairs of collars one pair encircling said bearing portions of said worm and extending peripherally of the worm, and thel other pair encircling said bearing portions of said worm wheel and extending peripherally beyond said worm wheel, and a housing for said Worm and worm wheel and including a pair of substantially semi-cylindrical end walls, one providing a seat for one pair of collars and' the other .providing a seat forl the other pair of collars, and side walls engaging the outer ends of said end walls and secured together and to said end walls to hold said worm and Worm wheel in position in said casing.

CHARLES G. KELLER. 

